Russia carried out air strikes in some parts of the Syrian city of Aleppo after the rebels opposing the administration of President Bashar Assad seized some areas.

In recent days, there has been the most significant attack against the Syrian government in years and the withdrawal of its army from Aleppo, the country’s second largest city.

Russia’s air force played a key role in keeping Assad in power after the country’s civil war broke out in 2011, but Saturday’s air strikes were the first on Aleppo since 2016.

More than 300 people, including at least 20 civilians, have been killed since the offensive began, according to the UK-based Syrian Observatory for Human Rights (SOHR).

The civil war has remained largely dormant since a ceasefire reached in 2020, but opposition forces still control the northwestern city of Idlib and much of the surrounding province.

Idlib is located just 55 kilometers (34 miles) from Aleppo, which was a rebel stronghold until it fell to government forces in 2016.

The current offensive, launched on Wednesday, is led by a jihadist group known as Hayat Tahrir al-Sham (HTS) and allied groups backed by Turkey.

HTS was considered one of the most effective and deadly of the groups fighting against the Assad government and was already the dominant force in Idlib.

Rebels have taken control of Aleppo’s airport and dozens of nearby towns, according to SOHR.

They also announced a curfew that will come into force at 17:00 local time (14:00 GMT) and will remain in effect until Sunday.

The Syrian military said rebels launched a “broad offensive from multiple axes on the Aleppo and Idlib fronts” and that the fighting took place “over a strip exceeding 100 km (60 miles).”

The organisation, which said dozens of its soldiers were killed, acknowledged that rebels had entered “a large part” of Aleppo.

Government forces had stated that they had temporarily withdrawn from Aleppo, but had previously stated that they were preparing a counter-attack.

Pictures showed roads leading out of Aleppo jammed with cars as residents tried to leave on Saturday.